The present invention relates to the monitoring of engine working hours, such as vehicle and other fuel-driven engines, as for the purpose of monitoring the total work done by the engine, and, if desired, for scheduling maintenance and fuel delivery and for similar purposes.
Among the conditions sensed locally at vehicle engines are run hoursxe2x80x94particularly important for monitoring the total work done by the engine, and, if desired, for scheduling fuel delivery and maintenance. Such scheduling, however, is impaired if there is no distinguishing between idling hours and working hours, including taking into account different workloads being performed that bear upon fuel consumption and engine wear and the like.
An approach to trying to ascertain these different running conditions is the monitoring of fuel consumption. Such sensing, however, is not only complex, but it is not really definitive in distinguishing information on idling vs. varying load working. This approach can thus generate an inaccurate metric of the total work done by the enginexe2x80x94for example, for scheduling maintenance needs.
In accordance with the present invention, on the other hand, distinguishing the conditions of the engine running idling from the engine actually working, and with different degrees of working loads, is attained through monitoring the alternating-current frequency of the engine alternator that corresponds to the engine speed (revolutions per minute). That frequency varies over time with engine operationxe2x80x94say, from relatively lower frequencies, say about 200-300 Hertz, or even lower frequencies, as characteristic of idling; and, above that threshold, up to higher frequencies of about 500-600 Hertz, more or less, for substantial fuel-consuming working of the engine on loads.
The principal object of the invention, accordingly, is to provide a new and improved method of and apparatus for differentiating and indicating engine idling periods with little fuel consumption, and periods of engine working under load and substantially consuming fuel, and that shall not be subject to the limitations of the above-described fuel-tank measurements and other prior approaches; but that, to the contrary, through monitoring the frequencies of the engine alternator corresponding to the engine speed over time, provides improved measurement of engine substantial fuel-consuming work run-hour measurements.
Other and further objects will be explained hereinafter and are more fully delineated in the appended claims.
In summary, however, the invention contemplates a method of measuring fuel-operated engine running hours, that comprises, monitoring the values of the frequencies corresponding to the engine speed over time, and processing the same to distinguish frequencies representative of engine idling periods and frequencies representative of engine-working periods, thereby to enable the measurement of engine-working hours.
Preferred and best mode implementations are later detailed.